The present invention relates generally to an apparatus and method of attaching and aligning reinforcing bars in a framework for supporting a concrete matrix. More particularly, this invention pertains to clips for joining reinforcing bars in a framework. Even more particularly, this invention pertains to a clip with flared legs for joining pairs of reinforcing bars in a parallel orientation.
It has been long known in the art of reinforced concrete structures to provide fastening means for aligning and attaching reinforcing bars in a framework prior to encasing such bars in a concrete matrix. One well known fastening means used in forming a framework of reinforcing bars is to wrap adjacent bars with wire ties, or other similar binding materials. Another well known fastening means is to attach such reinforcing bars by welding instead of wrapping. Both of these fastening means provide for attaching bars arranged in either transverse or parallel orientations. However, both means are labor intensive and, thus, more expensive when compared to the use of more recently developed reinforcing bar clips.
Plastic clips have been developed to provide a means of rapidly attaching adjacent reinforcing bars that are arranged in transverse orientations. For example, Padrum, in U.S. Pat. No. 4,110,951, teaches a plastic U-shaped clip formed by two opposing flanges extending from a base. Each of the flanges is split to form opposing and aligned openings within each flange. The clip is positioned and aligned above two reinforcement bars that are in a transverse orientation to each other. Pressure applied to the base causes the first reinforcing bar to be forced between the flanges and held in an upper position. Continued application of pressure upon the base causes the second reinforcing bar to be forced between the opposing split opening in the flanges and held in a lower position independent of the first bar.
A second example of prior art plastic clips is shown in U.S. Pat. No. 5,626,436 to Dragone. The Dragone clip is a U-shaped assembly comprising two parallel longitudinal members connecting two opposed hook assemblies. Each hook assembly comprises two connecting members, each extending from one of the longitudinal members, and a fulcrum section. A hook is formed by two opposing fingers, each attached at an opposite end of the fulcrum section and extending from the fulcrum section in a direction away from the longitudinal members. A gap is formed between each pair of opposing fingers. To install the Dragone clip, a first reinforcing bar is forced between the two opposed hook assemblies and held in an upper position against the parallel longitudinal members. The parallel longitudinal members are squeezed together by the user, causing each pair of opposing fingers to spread apart. The user slips the spread fingers of the opposing hooks over a second reinforcing bar that is positioned transverse to the first bar. The user then releases the parallel longitudinal members. As the parallel longitudinal members separate, each pair of opposing fingers close around the second bar and hold it in a lower position. The Dragone clip is sized so as to hold the second bar against the first bar.
One shortcoming of these two plastic clips is the limited orientations in which they can be used. These clips can only be used with transversely oriented reinforcement bars. However, frameworks of reinforcement bars frequently require attachment of bars in parallel orientations as well as transverse orientations. Previously, no clips existed to attach reinforcement bars in parallel orientations. Where frameworks are constructed using either of the prior art clips, the user can only use such clips to attach transversely oriented bars. All other attachment orientations require the user to employ more labor intensive methods of attaching the bars, such as wire wrap. What is needed, then, is a reinforcement bar clip that can be used to attach adjacent reinforcing bars arranged in a parallel orientation.
To make the task of attaching reinforcement bars in a framework as simple as possible, it would be advantageous if only one type of clip were necessary to join reinforcement bars in either a transverse orientation or in a parallel orientation. Therefore, what is additionally needed is a reinforcement bar clip that can be used to attach adjacent reinforcing bars arranged in either a transverse orientation or in a parallel orientation.